摘要
落叶松褐锈病对林木当年生长无明显影响，但对第二年生长影响显著。连年发病损失量剧增；不同病情指数（Ｘ）每公顷材积生长损失量为Ｙ＝１９４／１＋ｅ５４９３３７－００６８９３Ｘ；该病为害指标———病情指数为３６。立木林价、防治效果和成本分别为Ｃ、Ｑ、Ｅ时，防治指标方程为：１９４Ｃ［１／１＋ｅ５４９３３７－００６８９３Ｘ－１／１＋ｅ５４９３３７－００６８９３（１－Ｑ）Ｘ］－Ｅ＝０；前一年９月份降水量（Ｘ３）、当年５月份平均气温（Ｘ１）和８月份相对湿度（Ｘ２）为测报因子。预测区域平均病情指数Ｙ＝５１８５＋３２５９６Ｘ１－０４２１０５Ｘ２＋００８６２７Ｘ３±６９。
The larch needle brown rust ( Triphragmiopsis laricinum (Chou)Tai) is a common larch fungal disease in the east of Jilin Province, China. The Larch ( Larix olgensis) stands infected in the first year generaly grow normally, but in the second year they are affected seriously, the growth loss increases greatly in the stand infected lasting 2 years or over 2 years. Regresion equation was developed to predict disease index ( X ) and volume losses of growth/hm 2( Y):Y=1 94/1+e (5 49337-0 06893X) . The injury index was defined as 35. The equation of the economic threshold was developed to describe the relations among standing volume price( C ), the efficiency of control ( Q ) and the cost of control ( E):1 94C[1/1+e 5 49337-0 06893X -1/1+e 5 49337-0 06893(1-Q)X ]-E=0. The equation of forecasting the mean disease index was: Y=5 185+3 2596X 1-0 42105X 2+0 08627X 3±6 9(Y: mean disease index, X 1 :mean temperature in May of the current year, X 2 :mean relative humidity of the current year, X 3 :mean precipitation in September of the last year).
出处
《林业科学》
EI
CAS
CSCD
北大核心
1998年第3期74-79,共6页
Scientia Silvae Sinicae
关键词
落叶松
褐锈病
为害指标
防治指标
预测
Larch needle brown rust, Injury index, Control threshold, Forecast
